YAPC::EU 2018 Glasgow Update!

Task/Respond-to-an-unknown-method-call/Phix/respond-to-an-unknown-method-call.phix

@@ -0,0 +1,30 @@
+enum METHODS
+
+function invoke(object o, string name, sequence args={})
+--(this works on any class, for any function, with any number or type of parameters)
+    integer mdict = o[METHODS]
+    integer node = getd_index(name,mdict)
+    if node!=0 then
+        return call_func(getd_by_index(node,mdict),args)
+    end if
+    return "no such method" -- or throw(), fatal(), etc
+end function
+
+--class X: Xmethods emulates a vtable
+constant Xmethods = new_dict()
+
+function exists()
+    return "exists"
+end function
+
+setd("exists",routine_id("exists"),Xmethods)
+
+--class X: create new instances
+function newX()
+    return {Xmethods}
+end function
+
+object x = newX()
+
+?invoke(x,"exists")
+?invoke(x,"non_existent_method")